Troublesome Silicone Lube

I’m stuck in a bit of a puzzle and can’t quite work out what’s happening. MrsL and I have relied on silicone lubricant for external play for years. Just a couple of weeks ago, she had me tied to the bed and edged me multiple times using it. When we apply silicone lube this way, I never experience any burning or itching. She uses such generous amounts that it flows down around my scrotum, which she then uses while handling my balls. That said, every time I wear it alongside my Steelheart device, I get an incredibly strong burning feeling at the base of my testicles. This sensation is particularly sharp during nocturnal erections in the evening and night hours. Does anyone else notice this? I suspect the heat comes from a reaction between the stainless steel and silicone interacting together? What do you think? Any advice? Cheers.